Segment Information - Summary Financial Infomation by reportable segments (Details) $ in Thousands	3 Months Ended
	Mar. 30, 2018 USD ($) segment		Mar. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Revenue, Net	$ 90,127		$ 82,943
Gross Profit	47,183		40,408
Operating Income (Loss)	$ (9,327)		(21,158)
Number of Reportable Segments | segment	2
Video [Member]
Segment Reporting Information [Line Items]
Revenue, Net	$ 71,748	[1]	74,342
Gross Profit	41,226	[1]	40,773
Operating Income (Loss)	1,995	[1]	(5,836)
Cable Edge [Member]
Segment Reporting Information [Line Items]
Revenue, Net	18,490	[1]	8,601
Gross Profit	8,640	[1]	2,210
Operating Income (Loss)	(1,513)	[1]	(6,080)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net	90,238	[1]	82,943
Gross Profit	49,866	[1]	42,983
Operating Income (Loss)	$ 482	[1]	(11,916)
Operating Income (Loss) [Member]
Segment Reporting Information [Line Items]
Prior period reclassification adjustment			$ 1,100

[1] The Company has historically employed an aggregate allocation methodology based on total revenues to attribute professional services revenue and sales expenses between its Video and Cable Access segments. Beginning in the fourth quarter of 2017, the Company has prospectively changed to a more precise attribution methodology as the activities of selling and supporting the CableOS solution have become increasingly distinct from those of Video solutions. The impact of making this change in the first quarter of 2017 compared to the Company’s historical approach was an increase in operating loss of $1.1 million from the Video segment and a corresponding decrease to the operating loss of the Cable Access segment. The Company believes that the updated allocation methodology will provide greater clarity regarding the operating metrics of the Video and Cable Access business segments.